1. Field of the Invention
The present invention relates to a robot for moving an object from a movable body, and particularly to a robot suitable for ejecting a molded product from dies of a molding machine.
2. Description of the Related Art
The ejectors for ejecting molded products from injection molding machines are generally separated into the following two types.
The ejector of the first type starts the ejection of a molded product when dies of a molding machine are fully opened. On the contrary, the ejector of the second type starts the ejection of a molded product according to the opening action of dies of a molding machine by way of a mechanical cam.
In the ejector of the first type, however, the ejection takes a long time because it starts after dies of a molding machine are fully opened.
The ejector of the second type is expected to eject a molded product more rapidly than the ejector of the first ejector; however, it occasionally takes a time longer compared with the ejector of the first type.
The ejection time described above means a time elapsed between the full opening and the full closing of dies of a molding machine.
The reason why the ejector of the second type takes a longer time is that the ejector of this type is suppressed in its moving speed depending on the magnitude of the power for moving the dies of the molding machine. Moreover, the ejector of the second type has a disadvantage in that it is not stopped directly after dies are stopped and also not stopped at a specified position because of a large inertia of the ejector.
Additionally, in the case of changing a cam curve for actuating the mechanical cam, the cam must be replaced; accordingly the cam curve cannot be easily changed, which makes it difficult to achieve the optimization of the ejection.